Absorption lithium

Lithium + tetracycline antibiotics —> enhanced toxicity of lithium due to increased lithium absorption and impaired excretion. 

Lithium absorption lines can be relatively easily observed and measured in stars. There are more than 100 hot, population-II halo stars which have been observed since the first measurements of Spite and Spite (1982)... 

Scharman EJ. Methods used to decrease lithium absorption or enhance elimination. J Toxicol Clin Toxicol 1997 35(6) 601-8. 

Tomaszewski C, Musso C, Pearson JR, Kulig K, Marx JA. Lithium absorption prevented by sodium polystyrene sulfonate in volunteers. Ann Emerg Med 1992 21(11) 1308-11. 

As might be expected, the presence of food in the gastrointestinal tract has been shown to affect lithium absorption and a diurnal variation in renal lithium clearance has been reported 183, 184). In our experiments, diurnal and other factors appeared to influence lithium pharmacokinetics to a greater degree than did formulation differences 182). We conclude that the practice of administering an early evening dose after a meal may delay the lithium peak sufficiently to reduce the possible discomfort of any transient side effects and may improve patient compliance. This is more important than the choice of preparation to be given. 

The primary sites of lithium absorption are the jejunum and ileum. Water-soluble lithium salts are easily and almost completely (90-100%) absorbed (Lehmann 1997b). Experimental data have shown that lithium transport from the intestine into the blood is a passive diffusion process that occurs paracellularly through the tight junctions (Davie 1991). 

Oral administration of sodium polystyrene sulfonate (SPS, Kayexalate) has been advooated to attempt to reduce lithium absorption, but there is insufficient evidence of safety or effectiveness. 

A number of studies of the mucosal mechanisms of lithium absorption in the gastrointestinal tract have shown that lithium [28,29], and indeed other metals [30-32], transfers across the tract not by passage through the cell but by paracellular transport via the tight junctions and pericellular spaces. Cellular transport mechanisms and carriers identified in cells may thus exist only for the domestic requirements of the intestinal cells themselves, which in turn protect their own milieu interieur by, as far as practicable, avoiding accumulation of externally derived metals [33]. 

FIGURE 5.1 L12 potential curves used for modeling lithium absorption spectra near the... 

Horton S, Tuerk Am, Cook D, Cook J, Dhurjati P. Maximum recommended dosage of lithium for pregnant women based on a PBPK model for lithium absorption. AdvBioinf2012 2012 352729. http //dx.doi.org/10.1155/2012/352729. Epub 2012 May 30. 

The high solubility of the salt and resultant low water vapor pressure (58) of its aqueous solutions ate usehil ia absorption air conditioning (qv) systems. Lithium bromide absorption air conditioning technology efficiencies can surpass that of reciprocal technology usiag fluorochlorocarbon refrigerants. 

Anhydrous lithium hydroxide [1310-65-2], LiOH, is obtained by heating the monohydrate above 100°C. The salt melts at 462°C. Anhydrous lithium hydroxide is an extremely efficient absorbent for carbon dioxide (qv). The porous stmcture of the salt allows complete conversion to the carbonate with no efficiency loss in the absorption process. Thus LiOH has an important role in the removal of carbon dioxide from enclosed breathing areas such as on submarines or space vehicles. About 750 g of lithium hydroxide is required to absorb the carbon dioxide produced by an individual in a day. 

The normal abundance of lithium-7 is 92.44 atomic %. Because of its low thermal neutron absorption cross section, ie, 3.7 x 10 °, highly enriched Li... 

Selective absorption of durene from heavy gasoline (bp 150—225°C) is possible using a version of UOP s Sorbex technology where the X zeoHte is made selective for durene by replacing the exchangeable sodium cations with lithium ions (16). 

A typical absorption curve for vitreous siUca containing metallic impurities after x-ray irradiation is shown in Eigure 12. As shown, the primary absorption centers are at 550, 300, and between 220 and 215 nm. The 550-nm band results from a center consisting of an interstitial alkah cation associated with a network substituent of lower valency than siUcon, eg, aluminum (205). Only alkaUes contribute to the coloration at 550 nm. Lithium is more effective than sodium, and sodium more effective than potassium. Pure siUca doped with aluminum alone shows virtually no coloration after irradiation. The intensity of the band is deterrnined by the component that is present in lower concentration. The presence of hydrogen does not appear to contribute to the 550-nm color-center production (209). 

Properties. Most of the alloys developed to date were intended for service as fuel cladding and other stmctural components in hquid-metal-cooled fast-breeder reactors. AHoy selection was based primarily on the following criteria corrosion resistance in Hquid metals, including lithium, sodium, and NaK, and a mixture of sodium and potassium strength ductihty, including fabricabihty and neutron considerations, including low absorption of fast neutrons as well as irradiation embrittlement and dimensional-variation effects. Alloys of greatest interest include V 80, Cr 15, Ti 5... 

The commercial ores, beryl and bertrandite, are usually decomposed by fusion using sodium carbonate. The melt is dissolved in a mixture of sulfuric and hydrofluoric acids and the solution is evaporated to strong fumes to drive off siUcon tetrafluoride, diluted, then analy2ed by atomic absorption or plasma emission spectrometry. If sodium or siUcon are also to be determined, the ore may be fused with a mixture of lithium metaborate and lithium tetraborate, and the melt dissolved in nitric and hydrofluoric acids (17). 

Absorption Refrigeration Systems Two main absorption systems are used in industrial application lithium bromide-water and ammonia-water. Lithium bromide-water systems are hmited to evaporation temperatures above freezing because water is used as the refrigerant, while the refrigerant in an ammonia-water system is ammonia and consequently it can be applied for the lower-temperature requirements. 

The ammonia-water absorption system was extensively used until the fifties when the LiBr-water combination became popular. Figure 11-103 shows a simplified ammonia-water absorption cycle. The refrigerant is ammonia, and the absorbent is dilute aqueous solution of ammonia. Ammonia-water systems differ from water-lithium bromide equipment to accommodate major differences Water (here absorbent) is also volatile, so the regeneration of weak water solution to strong water solution is a fractional distillation. Different refrigerant (ammonia) causes different, much higher pressures about 1100-2100 kPa absolute in condenser. 

Methylindole has also been prepared by lithium aluminum hydride reduction of 1-methylindoxyl. Compounds giving rise to NH absorption in the infrared (indole, skatole) can be completely removed by refluxing the crude 1-methylindole over sodium for 2 days and then distilling the unreacted 1-methylindole from the sodio derivatives and tarry decomposition products. 

---